Electric lamp



Feb. 6, 1934.

'r. OHARA r AL ELECTRIC LAMP Filed March 3, 1928 Patented Feb.

UNITED STATES PATENT OFFICE Emao'raio LAMP Kotaro Enomoto, and K0 Honda,assignors of one-fifth to Kanichiro Matsuki, Tokyo, Japan ApplicationMarch 3, 1928. Serial No. 258,955

Tsuneto Ohara,

Tokyo, Japan,

1 Claim.

of them is disposed on the periphery of the neck portion and the otheris mounted on the end of the neck portion.

It is the object of the present invention to provide an incandescentelectric lamp which is more durable and lower in cost than present formsof electric lamps and can be handled with greater convenience than thetypes of electric lamps now known.

Incandescent electric lamps having their bulb portion and neck portionintegral have been proposed before. Usually,

however, such lamps have been so constructed as to necessitate a springmember. or other metal member, for establishing contact with thefilament. In consequence, such bulbs have been quite expensive becauseof the greater labor and care required in their manufacture.

The advantages inherent in the elimination of the usual metal base havetherefore been more than balanced by the disadvantages of the increasedcost.

on the other hand.

The present invention, concerns the provision of an incandescent lamphaving its bulb portion and its neck portion formed of a single piece ofglass and having its filament terminals so mounted as to permit the useof the bulb in the The fact that the lamp bulb 'is of lamp socket.formed of a single usual form piece of glass, instead of a number ofseparate portions joined together, makes it considerably stronger andmore durable than previous forms of lamp bulbs made entirely of glassand, furthermore, the mounting of the filament terminals in such amanner as to form of lamp bulb can considerably lower the bulb in astandard socket,

the present improved type of and all. occasions where 'the base lampbulbs are ordinarily entirely of glass, the present be manufactured at acost than lamp bulbs requiring a metal base, and due to the smoothsurface of the glass neck portion,

a lamp bulb of the type contemplated by the present invention can bemore readily mounted and disconnectedfrom a lamp socket than the variousforms of all glass lamps heretofore in use.

For a better understanding of the invention,

reference is made. ing wherein:

to the accompanying draw- Fig. 1 is a side view of a lamp in accordancewith the invention.

Fig. 2 is a longitudinal section of the lamp shown in Fig. 1.

Referring to the lamp is of the us portion a enclosing drawing more indetail, the ual shape'having a bulbous the filament, and a neckporimprove the lighting characteristics of the lamp.

the filament supporting tion 19 formed integral with the portion a andprovidedwith a screw threaded surface at to permit the mounting of thebulb in a customary form of socket. As shown in Fig. 2, the neck portionb and the bulbous portion a are integral and formed of a single piece ofglass.

The filament is supported inside the bulb a by means of a filamentsupporting tube extending inwardly into the neck portion. In its finalform, shown in Fig. 2, the tube is joined to the neck portion b at theend thereof so as to provide a continuous structure of glass. The leadwires 0 from the filament extend through the supporting tube toward theend of the neck portion 1), one of the lead wires terminating'in aterminal mounted on the periphery of the neck portion an-dthe other leadwire ending in a terminal-so mounted as to close the open end of thesupporting tube and provide a substantially flat base for the bulb.

As is evident from the drawing, the bulbous portion a and neck portion bare continuous and so formed as to provide a smooth outer surface havingneither a step nor a shoulder of the nature'common to the all glasslamps heretofore filament supportingmounted on the. neck portion b as toeliminate the necessity for any metal contact rings or plugs, therebysimplifying the construction of the lamp. If desired, the neck portion bmay be frosted to We claim:

A glass incandescent electric lamp having all except the filament andterminals in one piece. comprising a bulbous portion, said bulbousportion merging into a cylindrical neck portion having external screwthreads formed integrally therewith for fittingdirectly the end of saidneck beyond the screw threads into a lamp socket,

being turned inwardly to form a hollow filament supporting tube whichextends through said neck portion, afilament within the bulb. and a pairof lead wires extending from the filament through tube, one of said leadwires passing through the glass where the neck portion turns inwardly toform the hollow tube and terminating in a filament terminal on the neckportion adjacent the socket end thereof and beyond the screw threads,the other lead wire terminating in a filament terminal located substan-vtially at the center of the inturned end portion of the neck.

TSUNETO OHARA.

KO'IARO ENOMOTO.

KO HONDA.

